The present invention is directed to an apparatus for cutting a length of material as it flows from a machine and, more particularly, to a radius blade cutting apparatus which automatically cuts a length of material upon completion of a manufacturing operation. The invention is especially useful with sewing machines as used in the manufacture of garments.
In manufacturing a garment, various specialized sewing machines are used for efficient assembly of particular pieces of cloth and for stitching of particular seams. For example, in sewing a binding tape or other strip of material over a raw seam of a partially completed garment or workpiece, a specialized machine may feed the strip of material from a spool into a presser foot for stitching to a workpiece which is passed under the presser foot. This type of sewing machine may be equipped with one of the available cutting devices to permit automatic cutting of the workpiece from the excess strip of material and the excess thread after stitching of the workpiece is completed.
Generally, two types of devices for automatically cutting the workpiece from the excess strip of material and the excess thread are available. In one, a chopper blade and anvil are mounted upon the head and arm of the sewing machine, respectively, so as to chop the material upon actuation of a fluid cylinder. In another, a knife blade is pivotally mounted on the head of the sewing machine so as to engage a stationary blade mounted on the arm of the sewing machine upon actuation of a fluid cylinder. Generally, other types of cutting devices are not used in such machines due to the limited space available and the need to leave the throat of the sewing machine unobstructed for manipulation of the workpiece under the presser foot.
Although these available automatic cutting devices have significantly improved the efficiency of various garment manufacturing operations, the devices are unreliable in numerous sewing operations. Also, the chopper blade and anvil type device may break the arm or a portion of the arm off the sewing machine. Further, the knife blade type device is difficult to align and maintain in necessary alignment because the blades are mounted upon separate parts of the machine. And, both types of devices result in considerable expense and downtime when damaged or worn out cutting surfaces are renewed. Additionally, in many particular sewing machine applications, there is inadequate space for such devices without interference with operation of the machine.
It is, therefore, an object of the present invention to provide an apparatus for automatically cutting a workpiece from the excess strip of material sewn thereto without the difficulties inherent with the blade and anvil or the pivoting blade and stationary blade devices now available.
Another object of the present invention is to provide a cutting apparatus which is suitable for many diverse applications, particularly those machine applications where there is inadequate space for the available cutting devices, for cutting a strip of material as it flows from a machine.
It is still another object of the present invention to provide a cutting apparatus for cutting a strip of material as it flows from a machine such that positive cutting is achieved with a minimum of alignment requirements and without risk of injury to an operator of the machine.
It is still another object of the present invention to provide a cutting apparatus having reversible blades and other features to minimize machine downtime and other expenses of forming, installing, and renewing the cutting surfaces.